Why do turtles become cold stunned?

Sea turtles are ectotherms (cold-blooded), meaning that they can not internally maintain their body temperature and must absorb heat from the surrounding environment to stay warm. If exposed to temperatures under 10ºC for a prolonged time, sea turtles will suffer from “cold-stunning”, or hypothermia. When this happens, the turtles will suffer from many problems, increasing a decreased metabolic rate, slow heart beat, feeling lazy, for instance. If turtles remain cold for too long, they can die as their body literally shuts down.

Green sea turtle swimming in the blue, Maldives. Image.
Green sea turtle swimming in warm tropical water in Maldives.


  • Anderson, E. T., Harms, C. A., Stringer, E. M., & Cluse, W. M. (2011). Evaluation of hematology and serum biochemistry of cold-stunned green sea turtles (Chelonia mydas) in North Carolina, USA. Journal of Zoo and Wildlife Medicine, 42(2), 247-255